The site corresponds to a complex that brings together several wetlands: the bay (or lagoon) of Khnifiss and the vast sebkhas that extend it to the South (Sebkha Tazra) and to the West (Sebkha Mzeira), the adjacent marine coast. The bay is characterized by a significant diversity of habitats and high biological productivity. It is a vital stopover area for migratory birds using the East Atlantic route.

A real obstacle to the advance of the sandy dunes to the East, the bay dominates the entire landscape, with several habitats. The site is home to a varied fauna of marine invertebrates (36 Polychaetes, 96 Crustaceans and 57 Molluscs...), 17 species of amphibians and reptiles are also recorded there, among which two are Moroccan endemics: Tarentola boehmei and Bufo brongersmai. Bird populations total 179 species.

27 species of Mammals are present, two of which are endemic to Morocco (Gerbillus occiduus and Crocidura tarfayaensis) and one (Atlantoxerus getulus) is endemic to the Maghreb and the site coincides with its southern limit of global distribution.